Recreational genome sequencing for the whole family

Mark Henderson breaks the news of the first sequencing of an entire nuclear family for non-medical (read: recreational) reasons. John West, his wife and two teenage children (aged 14 and 17) apparently paid the full retail price of almost US$200,000 (update: in the comments, Mark writes that West apparently got a “small” but not “hefty” discount off this retail price) to sequencing company Illumina to generate their complete DNA sequences.

The West family members are no strangers to sequencing – John West is the former CEO of Solexa, the sequencing technology company purchased by Illumina in 2007 and whose platform is the basis for Illumina’s market-dominating Genome Analyzer sequencing instruments.

Much of Henderson’s article explores the intriguing ethical conundrum posed by sequencing children without a compelling medical reason to do so:

Some doctors and ethicists argue that while DNA data may prove medically useful, there is not enough evidence of benefit to warrant testing healthy children. Sequencing could reveal unwelcome information, such as a high risk of Alzheimer’s disease or misattributed paternity, which an individual may later decide he or she would rather not have known.

John West himself is seemingly unperturbed by the ethical issues here:

“A few years from now I think it will be ethically improper if you don’t have your children sequenced. What kind of parent are you if you don’t give your children a small amount of money to find out things that can help their health? We could easily get to the point where it is considered negligent not to do this.”

(As an aside, I love that $48,000 is a “small amount of money” – perhaps I could borrow some pocket change from West to get my own genome sequenced?)

“I don’t think you can argue at this point that genome sequencing is in the best interests of children, or that it couldn’t be done when they are older.”

I’ve personally got no ethical problem whatsoever with the Wests deciding to get their genomes sequenced. The medical benefits will likely be negligible, but then so are the potential harms (weighted by their probability), and a bright 14-year-old is more than capable of weighing these harms and giving informed consent.

There’s also a good scientific rationale for sequencing multiple family members: it improves the accuracy and interpretability of each individual’s sequence. This was ably demonstrated in a recent publication in which a family of four was sequenced by Complete Genomics in a hunt for a serious disease gene: that paper showed that combining data across multiple family members allowed analysts to dramatically improve the accuracy of sequencing. In a press release West points to a second advantage:

“By sequencing a family of at least four we can go a step further to interpret compound heterozygote variations in genes – those cases where multiple variations in a single gene, but on opposing chromosome copies, combine as a virtual homozygote. I expect that these are much more prevalent, and the source of much more phenotypic variability, than previously understood.”

This is a little opaque, but West is referring here to the ability to use family data to very accurately determine “haplotype phase” – that is, to infer which genetic variants are derived from maternal vs paternal chromosomes. If phase is known, it’s possible to determine whether two potential loss-of-function variants in the same gene are present on the same copy of that gene, or whether the person carries two separate defective copies. The latter case is far more likely to prove medically relevant than the former, but for an individual genome without family data these scenarios are extremely difficult to tease apart.

Anyway, my sense here is that the ethical problems posed in this case – especially the far-from-compelling “right to ignorance” claim – are outweighed by the principle that individuals should have autonomy to explore their own genetic data should they wish to do so. So long as the Wests have weighed up the benefits and harms and are capable of providing informed consent there’s no compelling reason for them not to be able to access their own DNA.